3 amp fuse blown twice, is it the pump?

[lifesagasman]

does the fuse blow when the boiler power switch is off?

 

[jackecole]

There's no separate switch to the boiler, just the spur switch in the cupbaord that turns power off to the whole system: programmer etc

 

[lifesagasman]

no power switch anywhere on the boiler?? are you certain?

 

[jackecole]

There's no isolation switch to turn the boiler off only. And no switch on the boiler itself either.

 

[lifesagasman]

does the boiler stat act as a switch (eg anti-clock to off)

 

[jackecole]

yes I can turn the boiler stat down. Sorry I've just moved here and not used the boiler stat or anything before. Shall I turn the boiler stat down to off? I'll have a look under the user control cover at the bottom of the boiler.

 

[lifesagasman]

ok, if the stat is also the power switch, when it's off you should have effectively taken the boiler out of the equation. i'll ask if the fuse still blows, if not,perhaps it could be the fan, try disconnecting it. i think next you'll need to get busy with a multimeter and measure for shorts, but it's not easy to advise from a distance so i'll leave it to your discretion

 

[jackecole]

Hi

I can turn the boiler off at the boiler (after looking now), now when I did this and put a new 3 amp in the spur the fuse is OK. So it must be a fault in the boiler as you have kindly suggested.

Please can you advise me I have a multimeter and can work safely with it.

I'm ready to find this short. Should I check inside the boiler for any loose/uninsulated wires first?

 

[lifesagasman]

i can't 'advise' you on what to do next, except to say be methodical. if you disconnect entirely the power cable you can do continuity tests.
that's as much as i can say. health and safety, you know.

 

[jackecole]

Ok fair enough, thanks for your help though.

Continuity test across Fans Live and Earth / Neutral and Earth and a contuity/low reading, ie . 01 etc on meter screen would indicate a short in the fan though?

 

[lifesagasman]

sounds that way to me. for more info search 'fan resistance'. i guess it's been posted before

 

[jackecole]

Ok, thanks I will crack on with this shortly. I'll test the fan first and check for any loose/pinched/uninsulated wires.

 

[Agile]

You dont seem to have enough experience to be able to test a fan by measuring the resistance.

All I could suggest would be to disconnect the fan and see if the fuse still blows.

However I cannot advise you to access the fan for that test as it would involve opening the combustion area of the boiler.

So all I could suggest is that you disconnect the fan from outside the combustion areas.

Tony